Computers are often used to automate repetitive tasks. Repeating identical or
similar tasks without making errors is something that computers do well and
people do poorly.

Repeated execution of a sequence of statements is called iteration. Because
iteration is so common, Python provides several language features to make it
easier. We’ve already seen the for statement in a previous chapter. This is a very common
form of iteration in Python. In this chapter
we are going to look at the while statement — another way to have your
program do iteration.